1. Field of the Invention
The present invention generally pertains to a wiring system for a wire harness, with applications for electrically connecting electrical devices depending from a sliding door of a vehicle to the main body portion. Such a sliding door is commonly found in some types of road vehicles, e.g. automobiles.
2. Description of Background Information
A sliding door system is frequently adopted in a single-volume (or xe2x80x9cmonospacexe2x80x9d) car, RV car (recreational vehicle), or van. The door slides freely in front-to-rear and rear-to-front directions (along the vehicle""s length direction). Such a sliding door is usually equipped with various electrical devices such as touch sensors for preventing door-pinching, loudspeaker systems for an audio system, and the like. In order to supply power to these electrical devices, a wire harness is extensively wired from the body of a vehicle into its sliding door, and is then taken inside the sliding door in an appropriate manner.
FIGS. 1A, 1B and 1C show a commonly adopted wiring system for a vehicle sliding door wire harness. The sliding door 2 moves forward and backward along the vehicle""s length. A door is opened (giving access to a door opening 1a) or closed, in accordance with its sliding displacement. The inside lower end 2a of the sliding door 2 is provided with a box-like harness housing 3 including a guiding channel 3a. Alternatively, the harness housing 3 may be installed in the vehicle""s body 1, depending on the type of a vehicle.
The wire harness is led from inside the vehicle""s body 1 through to inside the sliding door 2. For this purpose, a first group of electrical cables W1 is wired from the body 1 to the sliding door 2. The former is then fitted with an end portion A of a flat harness C. The flat harness C is folded over itself in the harness housing 3 to form a U-shaped loop portion, so as to provide sufficient spare length therein. Another end portion B of the flat harness C is connected to a second group of electrical cables W2, which is wired into and inside the sliding door 2. The first group of electrical cables W1 and the flat harness C are connected through a first harness connector CA, while the second group of electrical cables W2 and the flat harness C are connected through a second harness connector CB. The first harness connector CA carries a sliding device which engages with the guiding channel 3a of the harness housing 3 in a freely slidable way. The second harness connector CB is fixed to the harness housing 3.
FIG. 2A shows the condition of the above wiring system harness when the sliding door 2 is closed. The first group of electrical cables W1, wired between the body part 1 and the sliding door 2, is positioned at the rear side of the sliding door 2, while the second harness connector CB, contained in the sliding door 2, is placed in the front side relative to the first harness connector CA. The flat harness C is then maintained in a U-shaped looped configuration. FIG. 2B shows a condition when the sliding door 2 is opened. In this case, as the sliding door 2 is being opened, the harness housing 3 moves rearward relative to the first harness connector CA connected to the body part 1. In the harness housing 3, the first harness connector CA is placed forward, relative to the second harness connector CB. In this manner, the flat harness C changes its shape in the harness housing 3 with the opening and closing movements of the sliding door 2.
In a known wire harness system applied to a vehicle sliding door, a flat harness is folded and provided with a looped extra-length portion, so that the latter can follow the opening and closing movements of the sliding door. However, problems arise because there is little space available between the top and bottom faces of the sliding door. The flat harness must therefore have a very high bending capacity. It must also have a high wear resistance, because the opening and closing of the sliding door has a rubbing action. For these reasons, a so-called xe2x80x9cflat cablexe2x80x9d is used in place of the flat harness. FIGS. 3A and 3B shows another arrangement for a flat cable Cxe2x80x2, which may be adopted as a function of the type of vehicle. In this case, the flat cable Cxe2x80x2 folded in a U-shape loop portion is turned sideways, and the ex portion is extended or folded as the door 2xe2x80x2 opens or closes. A harness housing 3xe2x80x2 may have an open base, depending on the housing used.
However, when a flat harness or a flat cable is used for a folded extra portion, end portions of the flat harness or flat cable must be connected through first and second harness connectors respectively to a first group of electrical cables at the side of the vehicle""s  body part and to a second group of electrical cables at the side of the sliding door. Such a construction requires a number of component parts, and results in troublesome mounting operations. Moreover, the connector-fitting portions must often be reinforced by molding, in order to ensure reliable connections and secure a waterproof quality. This molding step increases operational steps and incurs higher costs.
The present invention was contemplated to solve such problems, and provides an integrated wire harness system ranging from the vehicle""s body to inside the sliding door, in which system the folded portion can be folded flexibly and possesses a high wear resistant property.
To this end, there is provided a harness-wiring system, in which a wire harness, including electrical cables, electrically connects a body of a vehicle to a sliding door thereof, one of the body and the sliding door including an enclosure, the wire harness including a lengthwise portion stored in the enclosure such as to form a folded portion having first and second enclosed end portions, so that the wire harness can follow opening and closing movements of the sliding door by changing the shape of the folded portion.
The above wire harness extends, as a joint-less continuous unit, from the body to the sliding door via the folded portion, and has first and second cable ends. The first cable end is adapted to fit with a body-side connector, while the second cable end is adapted to fit with a door-side connector. The wire harness is then placed inside a net-like sheath (net tube) for at least that part of folded portion. Such a net-like sheath is formed by knitting resin threads.
Alternatively, the wire harness may be placed inside the net-like sheath extending substantially from the body-side connector to the door-side connector.
Suitably, the folded portion further includes an elastic band, laid along the electrical cables at least at one locus of inside the net-like sheath and outside the net-like sheath.
Preferably, the system further includes a first clamping device including a pair of fixing pieces respectively including a semicircular recess, so that, when the fixing pieces are connected, both of the semicircular recesses form a holder. A hinge portion that pivotally connects the pair of fixing pieces is provided at one end of the pair of fixing pieces, and locking mechanism is located at the other end of the pair of fixing pieces, distal to the hinge portion, so that the first clamping device holds the first enclosed end portion of the wire harness by the pair of fixing pieces, and is locked by the locking mechanism.
Typically, the enclosure includes a first fitting device and the first clamping device includes a second fitting device, so that the first clamping device is fixed to the enclosure by fitting the first fitting device to the second fitting device.
Preferably yet, the system further includes a second clamping device including a pair of fixing pieces respectively including a semicircular recess, so that, when the fixing pieces are connected, both of the semicircular recesses form a holder. A hinge portion that pivotally connects the pair of fixing pieces is provided at one end of the pair of fixing pieces, and locking mechanism is located at the other end of the pair of fixing pieces, distal to the hinge portion, so that the second clamping device holds the second enclosed end portion of the wire harness by the pair of fixing pieces, and is locked by the locking mechanism.
Typically, the enclosure includes a first guide, and the second clamping device includes a second guide, so that the second clamping device is fitted to the enclosure by fixing the second guide to the first guide in a freely movable manner.
Preferably, the net-like sheath includes knitted resin threads.
The enclosure having the first guide may be a case or box including a slot which serves as a guide rail or channel. The case may be fixed to a sliding door or to a part of the vehicle body. Conversely, the enclosure may be prepared by transforming a panel, incorporating the panel into a part of the body or sliding door, and then forming a guide in the enclosure.
The wire harness according to the invention may be formed of electrical cables, continuously wired from the body of a vehicle to a sliding door. The same electrical cables form an extra-length portion folded in U-shape. This folded portion must satisfy a flexibility or foldability requirements. These requirements can be satisfied by providing the electrical cables, and wrapping them with a flexible and stretchable cylindrical net-like sheath. Moreover, this net-like sheath is resistant to wear, so that the electrical cables included therein do not suffer from wearing actions and ensuing damage.
The net-like sheath may be formed by knitting resin threads, e.g., nylon or PET, into a cylindrically shaped net structure. However, it can also be formed by making openings in a resin tube. The net-like sheath thus produced is stretchable. The sheath expands diametrically when pressed in a longitudinal direction, thereby facilitating the insertion of the electrical cables. The net-like sheath has sufficient flexibility to be flexed into a tight curve. Moreover, the resin threads and the portion covered therewith have a high level of hardness and anti-wear property, so that rubbing in the harness case does not create problems.
As the electrical cables are passed through the net-like sheath, the former is bundled and contained in the harness case while maintaining its foldability. The net-like sheath folded in a U-shape can change its shape smoothly, following the opening and closing movements of the sliding door. The inventive structure thus confers to the wire harness a flexibility and wear resistance at least equivalent to that obtained for known flat harnesses or flat cables. As a result, a wire harness, extending from the body to the sliding door, can be constituted only by continuously extending electrical cables. This can thus obviate the need for connectors hitherto used for connecting the flat harness and the electrical cables. Consequently, assembly steps and the number of component parts can be greatly reduced, and production costs are lowered.
Preferably, the electrical cables are placed inside the net-like sheath, continuously from the body-side connector to the door-side connector.
In such a construction, not only the folded portion, but the entire length of the electrical cables is covered with the net-like sheath. Thus, there is no need to use another protecting means e.g. a corrugated tube or a vinyl chloride tube. Assembling operations are thus simplified and can be effected efficiently.
Preferably, the folded portion includes an elastic band, e.g. a spring or resilient metal band, laid therealong, at least at one locus of the inside and the outside of the net-like sheath. When the resilient metal band is installed outside the net-like sheath, the metal band is preferably fixed to the net-like sheath by taping.
A droop tends to occur at the curved edge of the U-shaped folded portion. When the elastic metal band is extended along the electrical cables, this droop can be avoided. Nonetheless, the electrical cables and elastic metal band, passed through the net-like sheath, can still change their shape in conjunction with sliding door""s movements. Particularly, when the U-shaped folded portion is placed horizontally, instead of vertically, the curved edge of the folded portion tends to droop or hang down more easily. This droop creates friction with the harness case. If the bottom of the harness case is open, the droop will extend beyond the bottom of the sliding door. In such cases, the elastic metal band, aligned with the electrical cables, tends to reinforce the rigidity of the latter, and prevent such droop very efficiently.
Preferably, the system includes a first clamping device including a pair of fixing pieces which form a through hole when superposed, a hinge that pivotally connects the pair of pieces being located at one end of the pair of pieces, and locking mechanism located at the other end thereof, distal to the hinge. The first clamping device holds either the net-like sheath and the electrical cables together, or the cylindrical tube, the resilient band and the electrical cables together, by the pair of fixing pieces, and is locked by the locking mechanism.
In such construction, the net-like sheath is installed easily and securely. Alternatively, the net-like sheath can be fixed onto the electrical cables by taping.
The first clamping device used for fixing the net-like sheath onto the electrical cables may include a mount and a guide. This construction avoids having to prepare an extra clamp with a mount to be hooked with the harness housing, or another clamp with a guide to be applied to the electrical cables. The number of component parts is thus reduced, and mounting operations of the sliding door are simplified.
Furthermore, the system may include a second clamping mechanism having a second guide, the folded portion of the electrical cables having first and second ends. The first clamping device then clamps the first end of the folded portion from above the net-like sheath, and the second clamping device clamps the second end of the folded portion from above the net-like sheath, so that the second guide fits with the first guide in a freely movable manner.
Further yet, the system includes a first clamping device with a fitting mount, and the enclosure is fixed to the sliding door. The electrical cables, which are contained in the net-like sheath having first and second ends, are stored inside the enclosure in a U-shaped configuration. The first clamping device then clamps the electrical cables from above the first end of the net-like sheath, while the fitting mount is fitted with the enclosure may further include a second clamping device having a second guide, and the second clamping device clamps the electrical cables from above the second end of net-like sheath, so that the second guide is fitted with the first guide in a freely movable manner.